Flesch Reading Ease & Flesch–Kincaid Grade Level Calculator: Score Your Text
Paste text to get its Flesch Reading Ease score and Flesch–Kincaid grade level, with word, sentence and syllable counts, the hardest sentences and longest words, the sentence length that would hit a target grade, or enter your own counts.
How it works
Reading Ease = 206.835 − 1.015 × (words ÷ sentences) − 84.6 × (syllables ÷ words) · Flesch–Kincaid grade = 0.39 × (words ÷ sentences) + 11.8 × (syllables ÷ words) − 15.59
Rudolf Flesch’s 1948 Reading Ease formula scores text using only two measures: average sentence length and average syllables per word. Long sentences load working memory and long words tend to be rarer, so both lower the score. Most ordinary writing scores between 0 and 100; higher is easier, with 60–70 (plain English) a common target for the public. The scale is open at both ends: a text made only of one-word, one-syllable sentences reaches 121.22, and very long, dense sentences can score below zero. The Flesch–Kincaid grade level, developed for the US Navy in 1975, uses the same two measures to give a US school grade: 8.0 means an eighth grader should understand it. Because sentence length is weighted 0.39 and syllables per word 11.8, cutting the average word by 0.1 syllables lowers the grade by about 1.2, as much as cutting three words from every sentence. The calculator splits the text into sentences (handling abbreviations such as “e.g.”, initials, list items and headings) and counts syllables with rules and a list of irregular words. Tools differ in how they count, so compare drafts in one tool. If you already have counts, switch to Enter counts to apply the formulas directly. The formulas measure only length, not meaning, jargon or layout.
Worked example
The sample passage has 54 words in 3 sentences (18.0 words per sentence) and 93 syllables (1.722 per word; “readability” alone has 5). Reading Ease = 206.835 − 1.015 × 18 − 84.6 × 1.722 = 42.9, which is “difficult (college)”. Grade level = 0.39 × 18 + 11.8 × 1.722 − 15.59 = 11.8. To reach grade 8, sentences would need to be about 8 words long at the same vocabulary, or the words about 1.40 syllables each. The third sentence, at 26 words, is the hardest at grade 15.9.
Sources: Wikipedia: Flesch–Kincaid readability tests (score table and worked examples) · Readability Formulas: readability calculators and scales
Frequently asked questions
What is a good Flesch Reading Ease score?
For the general public aim for 60–70 (plain English, grades 8–9) or higher. Consumer instructions and health information often aim for 70–80. Academic and legal writing usually scores 30–50, and the Harvard Law Review scores in the low 30s.
What is the difference between Reading Ease and grade level?
Both use the same two measures. Reading Ease is a 0–100 style score where higher is easier; Flesch–Kincaid grade level converts the same inputs into a US school grade where lower is easier. A Reading Ease of 60–70 roughly matches grades 8–9.
Why do different tools give different scores?
They count syllables and find sentence ends differently: abbreviations, numbers, hyphenated words, headings and bullet lists are handled in different ways. Differences of a few points are normal, so compare drafts within one tool.
Can a Flesch score be negative or over 100?
Yes. “The cat sat on the mat.” scores about 116, and the maximum is 121.22. Very long sentences of long words can score below zero, and the grade level can go below zero for very simple text, down to −3.40.
How do I lower the grade level of my writing?
Split long sentences and replace long words with shorter ones. Each 0.1 syllable per word is worth about 1.2 grade levels, and each word cut from the average sentence about 0.4.
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